Droplet dynamics in a polymer electrolyte fuel cell gas flow channel: Forces, Deformation and detachment. II: Comparisons of analytical solution with numerical and experimental results

摘要

Proper water management (sufficient membrane hydration and effective liquid-water removal from catalyst layers, gas-diffusion layers, and channels) is key to achieving and maintaining the high performance of polymer electrolyte fuel cells (PEFCs). Specifically, liquid droplet formation and removal is an important issue in water management for PEFCs. In the first part of this series, explicit analytical solutions were derived by approximating the droplet shape as spherical and the Navier-Stokes equations were numerically solved to compute the forces over a droplet. In this second part of the series, results from numerical simulation using the Volume-of-Fluid (VOF) method and experiments are reported and they are compared with the analytical solutions derived previously. More specifically, experimental visualization of droplet dynamics in a micro channel is carried out. A high resolution CCD camera is employed to capture the droplet shape-change and detachment. Extensive numerical simulations via VOF are also performed to investigate droplet dynamics. Reasonably good agreements between analytical solution and VOF numerical simulation and experiment are obtained.